Subject: compact flourescents, mercury hazard?
Date: Tuesday, April 17, 2007 5:10 PM
Seems a bit extreme? Mercury hazard and/or yellow jounalism?
I'm not sure how much mercury is in these bulbs but here is what and
environmental group says:
Mercury toxicity depends on molecule that contains it. If it were that
toxic, all us older people would be dead from all the mercurochrome we used
to use ;)
Well, a compact fluorescent certainly contains a minute amount of
mercury. As has every regular fluorescent ever sold. I don't advocate
intentionally creating a mercury spill but I certainly don't panic about
a broken fluorescent. And I'm still trying to figure out what the first
linked URL means by "mercury powder". The powder in a any sort of
fluorescent bulb is the phosphor. The mercury is inserted during
manufacture as a small drop of liquid metal which partially vaporizes in
the vacuum and is ionized by the current through the tube.
I don't know how much mercury is in those bulbs but am surprised that
there is any at all. From what I understand, mercury is quite
hazardous in the environment and is very hard to get rid of once it's
You are correct to say that everone who is still alive has survived
mercury exposure. Too bad that the argument is weak. Folk who did
not survive are not here to answer your post or to speak to the issue
since they are dead.
I live in Minnesota which has a big mercury problem. It is airborne
from Canadian smokestacks. Ironically, some of our seemingly most
pristine lakes near the border are the most contaminated.
Some lakes have the equivalent of a skull and crossbones at the
lakeside. The warnings are always for little or no consumption of
fish from contaminated lakes for pregnant women and children. Adults
are only to be allowed two servings per week!! Many laugh off the
warnings but mostly they are fisherman and thus, expendable.
So mercury is no joke. I don't know how many have been poisoned but
I'm sure public health officials have an estimate. It is believed to
be under reported. and it is also believed that at least some
poisonings have been attributed to other causes.
For example, many miscarrages have occured where no test was ever made
for lead or mercury. Bottom line: mercury is worth avoiding and these
environmentalist should have taken the issue more seriously before
they promoted the bulbs. I cannot imagine that the bulbs can really
be "green" if they contain this poison.
No the argument is not weak. Toxicity of the mercury depends upon if it is
metallic or a compound and the type compound.
Most of the envirowhiners have extrapolated from toxicity of methyl mercury
which is extremely toxic to include all mercury compounds. I don't know
about you folks, but I've got several teeth with mercury amalgams in them
and I'm not having them removed ;)
As pointed out already, there really is only a tiny amount of mercury
used in fluorescent bulbs and is essential to its operation. And yes,
the chemical form of the elements are likewise important. An unbroken
bulb safely contains the mercury to the inside of the bulb. But chucking
large numbers of these bulbs with reckless abandon in landfills is not a
good idea. Proper collection and disposal is required.
Heavy metals (lead, arsenic, mercury, cadmium) are accumulated dose
poisons in that they are retained in the body for extremely long periods
of time before the body excretes them. For that reason even a low dose
continuously ingested over long time interval is just as dangerous to
health as a single large dose. A single low dose exposure entails
minimum risk. A good analogy is radiation risk. The patient gets only a
single dose but the administering technician must be concerned about
accumulated repeated dose. Still psychologically it is still disturbing
when the X-RAY technician runs and hides behind the lead shielding while
you lie there all alone for the X-ray.
This is a risk/benefit scenario, energy savings versus some proper
disposal control management.
Life is a compromise in many things.
Yes there is a small amount in all fluorescent lights. There is less the
1/1000 of an atmosphere pressure of gas in the fluorescent lamp that is
mostly argon with a small amount of mercury vapor. As electrons are
accelerated by the electric field they gain energy (hence the need for low
pressure to give the electrons a chance to travel far enough to gain this
amount of energy, they also need to be able to knock other electrons off of
the gas to keep the process going) and excite the argon atoms which transfer
the energy to the mercury atoms. The mercury gives up the energy as UV
light. The UV strikes the phosphors on the walls of the lamp which convert
the UV to visible light. Different types of phosphors give different types
of lamps their characteristic color. Fortunately this is a fairly efficient
process compared to regular light bulbs.
Hopefully we will have collection places for used fluorescent bulbs so that
the mercury won't go into landfills or incinerators. Even still the amount
of power saved reduces the total mercury pollution if coal is used to
generate the power.
Interestingly a year ago I was in Mexico and noted the extensive used of CFF
bulbs. I believe much of their power is generated with oil which would make
Yes it is extreme, and I would not even call it journalism.
Yes there is mercury in them, a very very small amount. All fluorescent
lamps have some. A number of years ago technology and regulation reduced
that amount to almost nothing. The Cf's have even less.
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